NEW YORK -LRB- CNN -RRB- -- Two former New York Police Department detectives were sentenced to life in prison without parole Friday for operating as Mafia hit men while employed by the NYPD .

Louis Eppolito , 60 , and Stephen Caracappa , 67 , who spent a combined 44 years on the force and once worked as partners , were found guilty in April 2006 of engaging in racketeering .

According to prosecutors , they were paid $ 4,000 a month by the Mafia and were personally paid $ 65,000 by Luchese crime family underboss Anthony `` Gaspipe '' Casso for killing another mobster during a phony traffic stop . Authorities said Casso regarded the officers as his `` crystal ball , '' likely referring to their alleged involvement in relaying classified information to the Luchese family .

Eppolito and Caracappa , who reiterated their innocence at Friday 's sentencing , were found guilty of participating in or aiding eight murders , two attempted murders and one murder conspiracy , as well as witness tampering , witness retaliation , obstruction of justice , money laundering and drug charges .

Eppolito was sentenced to life in prison plus 100 years , while Caracappa received life in prison plus 80 years . They were also fined a combined $ 4 million .

`` The sentences imposed today bring some measure of closure for the families of the victims of these defendants ' unspeakable crimes and for the citizens of the city whose trust these men betrayed , '' U.S. Attorney Benton J. Campbell said in a news release . `` We are gratified that the defendants will spend the rest of their lives behind bars . ''

Eppolito , who grew up in a Mafia family , wrote the book `` Mafia Cop , '' in which he described how he turned away from the `` family business '' to become what he said was one of the police department 's most decorated officers . He also had small roles in several films , including the role of Fat Andy in the 1990 mob film `` Goodfellas . ''

Caracappa was a member of the NYPD 's Organized Crime Homicide Unit , which he helped create .

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Louis Eppolito , 60 , was sentenced to life in prison plus 100 years

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Stephen Caracappa , 67 , received life in prison plus 80 years

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Prosecutors : Men killed mobster during a phony traffic stop ; were paid monthly

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Authorities say Mafia viewed them as `` crystal ball '' of classified information